Gromhalun

Gromhalun is a gift, born of fire and stone.

It breathes with the winds of innovation.

— Thormir Stoneshaper

Introduction

Pumice stone was long neglected; overlooked for millennia as little more than a curiosity. But one man, the exiled alchemist Thormir Stoneshaper, saw what others did not. He recognized its potential, embraced its properties, and risked the last of his reputation to reveal its value.

In the end, his gamble paid off.

Known to the dwarves as Gromhalun (meaning the "Breathing Stone"), pumice redefined how the dwarven people approached life beyond the depths. It became the cornerstone of Seastone: the most successful surface settlement in dwarven history. From naval engineering and heavy industry to housing and domestic comfort, pumice stone marked a turning point in dwarven innovation.

Origins

As dwarves say, Gromhalun is forged from the lungs of the earth.

It is formed when magma rich in volatile gases erupts violently and cools rapidly, trapping air bubbles inside a brittle matrix of volcanic glass and ash. The result is a stone light enough to float, yet capable of astonishing structural integrity when properly treated.

The coastal city of Seastone stands in a region rich with underground volcanic activity. The land around it hums with geothermal promise, and its shores are carved from old volcanic flows. Centuries ago, rivers of lava surged from beneath the coastal shelf, met the ocean, and shattered into sponge-like stone. Over time, the waves did the rest: eroding soft cliffside rock, dredging up loose deposits, and scattering pumice across the coasts.

Here, the sea breathes, and the stone answers.

Types of Pumice Stone

Though united under the name Gromhalun, not all pumice is born the same way. Its qualities - color, density, and resilience - are shaped by where it formed and how it was gathered. Seastone's artisans and miners have long studied these variations, categorizing the stone by origin to better match it to purpose

_{Seastone Crest}

Type

Stone

Value

5gp/cubic foot (regionally) or 15-25gp/cubic foot (exported)

Rarity

Low (regionally) or Moderate/High (globally)

Related Locations

• Seastone

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Modern uses of Gromhalun

Naval Engineering

Buoyant, resilient, and resistant to rot, pumice revolutionized dwarven shipbuilding. No longer shackled to the mountain halls, dwarves took to the waves aboard pumice-hulled vessels reinforced with strong wooden ribs. Lighter than traditional vessels, these ships navigate shallow waters and volatile currents with ease. Driftstones especially, prized for their weightlessness, are reserved for scoutships and vessels of exploration.

S.O.N.A.R.'s experimental ships are clad in pumice-reinforced hulls, designed to offer both buoyancy and resilience under strain, making them ideal for long-range exploration across dangerous waters.

Industrial Applications

In the steam halls and foundries of Seastone, Gromhalun reveals its truest strength. Workshops line their engines, forges, and pressure tanks with thick slabs of Rootstone to trap heat without weighing down delicate machinery. Its porous body makes it ideal for casting molds; molten metals take form cleanly within its sponge-like texture and cool without warping.

Even more revolutionary is the dwarven invention of pumice-clay cement - known locally as Grommortar - a lightweight, flexible building paste suited for multi-story constructions.

Architecture and Urban Design

Gromhalun turned Seastone into a city that grows upward. Entire neighborhoods climb the cliff faces, supported by pumice foundations that defy both gravity and erosion. Cliffstone, the most abundant variety near the surface, is favored for its insulating qualities and feather-light mass. Walls breathe and bridges arch boldly over sea-slick gaps. Dwarves, once bound by the depths, now live beneath open sky, held by the softest of stones.

Domestic Life

Even far from the thunder of hammers and the hiss of steam, Gromhalun finds its place. In Seastone’s homes, pumice whispers comfort. Ground fine, it is used to polish teeth, soften calluses, and smooth skin. A brick warmed by the hearth and wrapped in wool becomes a source of warmth passed between hands on winter nights; a tradition known as the Comfort Brick. In kitchens, it scours soot and grease from cast iron, scrubbing without damage.

Pumice stone is even used by children as it gives shapes to their favorite toys. Due to its malability, it takes the form of puzzle blocks, carved beasts, and floatable toy boats; safe to touch, soft to drop and light enough to carry.

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